Mexico on [October 3] launched a massive program to vaccinate fifth-grade girls against human papillomavirus, making it one of the few nations in the world with a universal campaign against the sexually transmitted virus. One million schoolgirls ages 11 or 12 will receive the HPV vaccination this week, Mexican President Felipe Calderon said. Another 200,000 girls who aren't in school also will be given the vaccine. Mexico becomes one of the few countries in the world to follow in the footsteps of Greece, which in 2007 made the HPV vaccination mandatory for girls entering seventh grade. All fifth-grade girls will be given an initial shot, then a second shot six months later. A third and final dose will be given to girls in ninth grade. Mexico began an obligatory vaccination program of schoolchildren and pregnant women in 1991, and currently [administers] 14 types of vaccines, Health Secretary Salomon Chertorivski said. During weeklong periods three times a year, thousands of doctors and nurses spread across the country to schools and rural clinics to administer the free vaccinations.